Screen printing, wherein ink is directly transferred onto a substrate, has grown dramatically over the past few decades into a very high volume business. Among the more popular items of wearing apparel carrying various printed indicia are billed caps. The printed indicia may include letters, numerals, designs or a combination thereof in one or more colors. Currently, caps are screen printed on manually operated, single station machines using either a flat or round cap holding platen or mandrel. Since the cap portion being printed is made in a round or cylindrical configuration, there are inherent problems using a flat platen associated with maintaining the most desirable relationship between the print screen and the cap. After the cap is printed and resumes its normal cylindrical shape, a certain amount of distortion is evident.
Using a round mandrel can significantly reduce the distortion problem, however, the complex action involved wherein the printing platen must move horizontally and also rotate presents difficult and heretofore unsolved problems in a carousel type, multiple station configuration.
While the prior art includes many types and forms of multiple station, multiple color printing machines using a flat platen for printing on a flat surface, those of ordinary skill have failed to provide an automated multiple station, multiple color printer for cylindrical surfaces such as caps which is capable of high volume, high quality printing in an economical manner.